He succeeded Leo
III, whose policy he continued. Immediately after his
consecration (in June 816) he ordered the Roman people to swear fidelity to the Frankish king Louis the
Pious, to whom he went personally in August of 816. After the
coronation of Louis at Rheims in October, he returned to Rome,
where he died in January of the following year. His successor was
Pope Paschal
I.